The evaluation of the thermal behavior of a material due to a severe electric discharge is required in the event that this material is in contact with areas in which there is a possible risk of ignition, for example and for the aeronautical field, in areas in contact with the fuel of the aircraft and/or with its gases. In this case, a prediction of the temperature reached in the material is required for the purpose of being able to prevent hot spots: the high current density in certain spot locations of the structure of the aircraft may cause high temperature spots. If this temperature exceeds 200° C. (ignition point of fuel considered by the FAA/JAA), the fuel may reach its inflammation point if the suitable concentrations are present inside the tank.
Structural damage (holes, melted material, peeling in the case of composite materials, etc.), which need to be known in order to prevent the mechanical behavior of the material after the impact, may occur due to thermal effects.
Until now aircraft structures have been manufactured mainly using metallic materials. Carbon fiber and resin composite materials currently tend to be used to manufacture aircraft structures. The main difference between both materials is that the metallic material is far more conductive than the composite. Therefore, when the effect of an electric discharge is produced in the structure of an aircraft, if it is a metallic structure, the current of this discharge is quickly distributed throughout the entire structure, which does not occur when the structure is made with composite material. This means that the local damage is less with metallic structures than it is in the case of using a composite material.
In the field of aeronautics, to obtain certification for a material it is necessary to conduct tests on the chosen material in certified laboratories for such purpose. These tests are very expensive and complex for the case of composite materials currently used in aeronautics.
The present invention is thus aimed at solving these drawbacks in the case of aircraft structures made of composite material.